LIGHT, SIGHT AND FIGHT FOR INSIGHT

The visual processes in the human retina begin with absorption of phot ons from light. This light energy is converted into electrical stimuli in a series of enzymatic steps which initiates neural responses to li ght. Therefore, any structural and functional abnormalities in these m olecules will likely interfere with signal transduction which may ulti mately lead to blindness. A new era began in 1990 with an ultimate goa l of redefining and developing new treatments for the photoreceptor di sorders by identifying mutations in the genes encoding phototransducti on cascade enzymes. As a result of this intense investigation around t he world, mutations have now been identified in eight genes, in severa l retinal dystrophies. Almost all of these genes encode signal transdu ction enzymes and all are highly expressed in photoreceptor cells. Thi s effort has been further aided by gene disruption technology. Althoug h there are many puzzles that need to be solved, these approaches have given some insight into the genetic eye disorders and will undoubtedl y improve our understanding of inherited eye disorders in the future. This improved knowledge may eventually lead to prevention or a cure. ( (C) Societe francaise de biochimie et biologie moleculaire/Elsevier, P aris).